We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-25 · 7 min read · Independent comparison
If you want smart features and long battery life, choose Promise Earbuds; if you need a tiny, discreet earbud built for sleeping and small ears, choose eleror Invisible Mini Earbuds.
• Promise Earbuds, biggest strength: A genuinely unusual feature set — a remote control for scrolling TikTok and YouTube Shorts, plus 40 hours of total playtime and a digital battery display on the case.
• Promise Earbuds, biggest trade-off: Bigger and more conventional in the ear, and the "noise cancellation" is ENC for calls only — there is no active noise cancelling to quiet a plane or a busy office.
• eleror Invisible Mini Earbuds, biggest strength: An ultra-compact 14mm body wrapped in soft silicone, which makes them a rare pick for side sleepers and people with very small ear canals.
• eleror Invisible Mini Earbuds, biggest trade-off: Only 6mm drivers and a shorter 30-hour total runtime, so they are built for comfort and discretion rather than big, room-filling sound.
• Who each is for: Promise Earbuds for commuters, gym-goers and anyone who wants features and battery; eleror for sleepers, small-eared users and anyone who wants an earbud nobody notices.
The Promise Earbuds are a feature-first pair of wireless earbuds, and the headline feature is one you will not find on most rivals: a remote control built into the earbuds that lets you scroll and like videos on TikTok and YouTube Shorts without touching your phone. If you have ever watched Shorts with wet hands in the kitchen, or propped your phone up while lying in bed, that single trick is the reason to look at these. It is a niche idea, but it is a genuinely useful one for a specific kind of buyer.
The rest of the spec sheet is solid, mainstream earbud territory. Bluetooth 5.3 with a 33-foot wireless range covers a phone in your pocket, a laptop across a desk, or a tablet on the other side of the room. Promise rates the battery at 6–8 hours per charge and up to 40 hours total with the matte black case, which charges in about an hour and shows a digital power readout so you can see what is left before you leave the house. The 13mm dynamic drivers are the biggest number in this comparison by a wide margin, and Promise tunes them for deep bass and crisp treble across genres — that is a size class you normally associate with a fuller low end.
It is worth being precise about the noise feature, because this is where buyers get tripped up. Promise uses ENC — Environmental Noise Cancellation — which is a microphone system that filters background noise so the person on the other end of a call hears you more clearly. It is not ANC. These earbuds do not actively cancel the noise around you, so do not buy them expecting a silent cabin on a flight. Promise is also upfront that the remote functions can need a little setup help, and it backs that with US-based customer support and a stated 2-month return policy.
Buy the Promise Earbuds if you want the longest runtime here, want the remote-control party trick for short-form video, and want a bass-forward 13mm driver. Skip them if your priority is an earbud you can barely feel while sleeping, or you specifically need active noise cancelling.
The eleror X9 is the opposite philosophy in almost every way. Its whole reason to exist is size and comfort. Each earbud is 14mm and about 3 grams — eleror compares it to something smaller than a US penny — and the entire body is wrapped in soft silicone. The design brief here is pressure relief and extended wear, not maximum output. The ergonomic shape is meant to sit in the concha of your ear and lock in with a small rotation, and eleror includes S/M/L ear tips so you can match your own canal instead of settling for whatever ships in the box.
That combination is what makes these a legitimate sleep earbud. Soft silicone, no hard edges, and a low-profile body mean you can lie on your side without a plastic shell digging into your ear. The same traits make them easy to live with on a commute, on a walk, or during a long study session — anywhere you want background audio without bulk. Natural noise isolation comes from the silicone seal rather than electronics, so you get some reduction of the world around you simply by having them in properly.
On the technical side, the X9 uses Bluetooth 5.4 — a newer version than the Promise — with a 10-meter range, a 6mm dynamic driver, and 16-ohm impedance at 90dB sensitivity, which makes them easy to drive from a phone. Playback is 6 hours per charge and up to 30 hours with the case, which recharges in about 2 hours. Calls run through an ENC microphone, and controls are all touch-based: double-tap to play or pause, triple-tap for volume, single tap to answer, long press to reject. The case itself is small — roughly 4cm by 3cm by 2cm — in a subtle gray that matches the "nobody will notice these" pitch.
Buy the eleror X9 if you have small ears, sleep on your side, or want an earbud that disappears. Skip them if you want big bass, the longest possible battery, or the extra smart features Promise offers.
Side-by-Side: Which Should You Choose?
• Best for sleep and side sleeping → eleror Invisible Mini Earbuds (3g each, fully silicone-wrapped, low-profile body).
• Best for small ears → eleror Invisible Mini Earbuds (14mm body with S/M/L tips included).
• Best for bass and overall sound scale → Promise Earbuds (13mm dynamic drivers vs. 6mm).
• Best for hands-free short-form video → Promise Earbuds (the built-in TikTok and Shorts remote).
• Best for discreet, barely-there looks → eleror Invisible Mini Earbuds (subtle gray, tiny footprint).
• Best for charger convenience → Promise Earbuds (digital power display on the case, 1-hour charge time vs. 2 hours).
• Best for newer Bluetooth → eleror Invisible Mini Earbuds (Bluetooth 5.4 vs. 5.3, though both are current and stable).
• Best for long-term coverage → eleror Invisible Mini Earbuds (a stated 1-year warranty vs. Promise's 2-month return policy).
If I were buying for myself, I would pick the Promise Earbuds. The reason is simple: the 13mm drivers, the 40-hour total runtime, the battery display on the case, and the video remote control cover more of my actual day — commuting, working out, watching clips — than any single comfort advantage would. That said, this is an opinion, not a universal answer. If you sleep with earbuds in, or standard buds have always felt too big and too hard in your ears, the eleror Invisible Mini Earbuds are the better buy, and I would not talk you out of them. Match the earbud to the job, not to the spec sheet.
They use ENC, which reduces background noise on phone calls so the other person hears you clearly. They are not ANC, so they will not actively block the noise around you. If you want a quieter world, that comes from fit and seal instead.
That is their strongest use case. At about 3 grams each with a full silicone wrap and a low-profile body, they are designed to reduce ear pressure during extended wear, including side sleeping. That is a comfort claim based on the design, so fit will still vary by ear.
The Promise Earbuds last longer on paper — 6–8 hours per charge and up to 40 hours with the case, versus 6 hours and up to 30 hours for the X9. Promise also charges faster at about 1 hour versus 2 hours.
The eleror X9 is the one built for that. Its 14mm body is deliberately compact and it ships with S/M/L ear tips. The Promise Earbuds are standard in-ear buds with rounded tips, which suit average ears better. Either way, check the current price on Amazon before you decide, since that can shift the value calculation.
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See also: Togetface Earbuds vs eleror Invisible Mini: True Wireless, AIKESI Mini Invisible Earbuds vs WUYUEGE, Zunate True Earbuds vs Honcas Mini Invisible Earbuds